ui/vdagent: factor out clipboard peer registration

This allows common code reuse during migration.

Note that resetting the serial is now done regardless if the clipboard
peer was registered or not. This should still be correct.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>

ui/vdagent.c

@@ -694,6 +694,18 @@ static void vdagent_chr_open(Chardev *chr,
     *be_opened = true;
 }
 
+static void vdagent_clipboard_peer_register(VDAgentChardev *vd)
+{
+    if (vd->cbpeer.notifier.notify != NULL) {
+        return;
+    }
+
+    vd->cbpeer.name = "vdagent";
+    vd->cbpeer.notifier.notify = vdagent_clipboard_notify;
+    vd->cbpeer.request = vdagent_clipboard_request;
+    qemu_clipboard_peer_register(&vd->cbpeer);
+}
+
 static void vdagent_chr_recv_caps(VDAgentChardev *vd, VDAgentMessage *msg)
 {
     VDAgentAnnounceCapabilities *caps = (void *)msg->data;
@@ -720,13 +732,9 @@ static void vdagent_chr_recv_caps(VDAgentChardev *vd, VDAgentMessage *msg)
 
     memset(vd->last_serial, 0, sizeof(vd->last_serial));
 
-    if (have_clipboard(vd) && vd->cbpeer.notifier.notify == NULL) {
+    if (have_clipboard(vd)) {
         qemu_clipboard_reset_serial();
-
-        vd->cbpeer.name = "vdagent";
-        vd->cbpeer.notifier.notify = vdagent_clipboard_notify;
-        vd->cbpeer.request = vdagent_clipboard_request;
-        qemu_clipboard_peer_register(&vd->cbpeer);
+        vdagent_clipboard_peer_register(vd);
     }
 }